Method of patching veneer sheets



Dec. M, i943.

P. F. sKooG 2,336,703

METHOD OF PATCHING VENEER SHEETS Original Filed April 2l, 1941 3 Sheets-Sheet 1 Dec. 14, 1943. P. F. SKOO'G 2,336,703

METHD OF PATCHINGVENEER SHEETS Original Filed April 21, 1941 3 Sheets-Sheet .96 i 96 20 76 v I 20 i i L55 l 76 I` l U l I 7 66 I I 74' I/ I 66A; 74 l l 687/ eef@ 28 "80 I/ a I I I 70 I Il lrl/ 26 I 42 60 64 96 Ffa., 1020 96 20 m l i 76 28 70 l I 987/ ff@ /20 l I 8@ l" 66 a 98 45 nialwucfamw 42 .;I'4//f//V7/I//7/// Patented Dec. 14, 1943 2,336,703 METHOD 0F PATCHENG VENEER SHEETS Alimer F. Skoog, Bellingham, Wash., assgnor to Machinery Corporation,

Olympia Plywood Olympia, Wash.

Original application A pril 21, 1941, Serial No.

389,533. Divided and this application September 29, 1941, Serial No. 412,808

4 Claims.

This invention relates to an improved method of patching veneer sheets and is particularly adapted for use in the patching of thin Wood veneer such as is produced in the lumber industry. In the practice of peeling logs, as cornpared to the older method of slicing the Wood, to form veneer sheets it is common to have certain pieces that are defective by reason of the fact that they have disguring knots or other marred areas.

This application is a division of application Serial Number 389,533, led by me April 21, 1941, which is co-pending at this time in the United States Patent Oice.

Ordinarily the patching and salvaging of such stock is a manual operation that requires a great amount of labor and is never satisfactorily done by hand. A suitable mechanically operable salvage means and method to effect such patching is desirable as such stock is usually of such low grade that it is unusable in the manufacture of plywood of the standard or better grades. In manually patching veneer stock it is customary for a workman to cut by hand With a sharp knife, a boatshaped patch, or to cut a round patch by the use of a rotary saw. Subsequently, usually at another location a patch is cut from a piece of similar patching stock. This patch is placed in position where it is glued in the cutout area from which the marred veneer has been removed. This forming of patching is usually a three-step operation, the first being the cutting operation, the second being the formation of a patch suitable to fit in the cut-out portion, and the third the placement of the patch and its gluing into the stock being patched.

Ordinarily such patching operations are formed in a series of steps along a table set aside for that purpose. A considerable amount of time is consumed in eiecting such patching. Patching is not, therefore, very satisfactory by this method because ordinarily it does not raise the grade suiiiciently to extend any material advantage to the industry to oiTset the cost. As a result much good material can only command a relatively low sale price.

An important object of my inventionis the provision of method and means for patching veneer sheets wherein the operation may be carried on at a single position and with great rapidity and efficiency.

Another object of my invention has been the provision of means for making a patch in veneer stock wherein the preparation of the material to be patched. the cutting of the patch, and the placement of the patch, is performed in a seriesv of sequenial steps all encompassed within a brief moment required for the'operation.

A further object of my invention comprises the provision of a method of cutting a patching plug plank to the size and shape of a punch-cut area to be patched and inserting that cut plug into said area while always maintaining the plug cornpressed against edgewise expansion and warping so that when the plug is nally placed it will securely engage in the area that is patched.

Still another object of my invention relates to the provision of means for punch-cutting a marred area in sheet veneer which means will clamp such sheet about the marred area and hold it throughout the cutting and patching steps of my method.

Another and further object of my invention relates to the provision of means for cutting and compressing a plug for placement in a veneer sheet while maintaining that cut plug against buckling or expansion as it passes through a cutting die, at oneedge of which the plug is cut, un

til it is inserted into the area being patched.

A further object of my invention is the provision of plug-cutting and patching mechanism which is simple to manufacture and easy to assemble and capable of constant use with a minimum of maintenance and repair, and which mechanism may be operated under electrically controlled, timed valving mechanism or the equivalent.

Other objects and advantages of the invention will be apparent in the course of the following description wherein I have described apreferred form of my invention as shown in the accompanying drawings.

Figure 1 is a detailed assembly view of my plugcutting and patching mechanism with portions shown in section and portions omitted for convenience of illustration.

Figure 2 illustrates the mechanism by which plug blanks are constantly fed for introduction into the patching mechanism,

Figure 3 is a bracketed view showing various types of plug which may be cut for use in patching operations practiced according to my described invention,

Figure 4 is an enlarged vertical sectional view of. he principal elements of the plug-cutting and patching mechanism together with the operating parts therefor,

Figures 5 and 5A show sequentially in plan the plug blank feeding mechanism as utilized .in my mechanism,

view of a fragment patching operation various parts and the various steps of my method.v

and means for patching veneer sheets.

Referring to the drawings. throughout which like reference characters indicate like parts, .numeral 20 designates a horseshoe-shaped frame member utilized for supporting the mechanism I have devised for cutting plug patches for veneer sheets. The lower arm 2| of the frame member 20 is supported upon suitable legs 22 and 23 that may be mounted upon a. work floor, the showing ofthe actual footing being eliminated for convenience of illustration.

By means of suitable structural members 26 a web table 26 is disposed within the arms of the iramei20 in a horizontal position for the reception of a sheet of veneer stock 26 that may be laid thereon for patching. While I have shown the sheet 28 as being of relatively small size it will be understood that it is intended that this mechanism is for the patching of extremely large size veneer sheets of the nature that are now commonly being cut in veneer plants.

Positioned adjacent the mouth of the frame member 20 is a pair ofsupporting legs 29 and 30, 30 which mount the table element 3| that is aligned horizontally with the table element 26. The legs 30, 30 are spaced apart and a vertically movable lifter bar 32 is guided therebetween. Bar 32 supports a plurality of plug patch blanks 34 as indicated in Figure 1. At its end member 32 has coupled thereto a cord or cable 36 that passes over sheaves 66 and 31 and has attached thereto a weight 38 that hangs at some remote point and constantly urges the member 32 upwardly. The blanks 34, resting on bar 32, are aligned on their forward edges against the plate 39 and on their rear edge they are kept in alignment by means of the shoe 40.

As the individual members of the group of plug blanks supported by the bar 32 are forced upwardly they come against the bottom face of stop block 4| that is positioned in a hole in plate 44 that is disposed just under the table 3|.

Supported on the lower arm 2| of the frame member 20 is a base block 42 that is adapted to be shifted for very careful adjustment by a suitable screw mechanism for proper positioning in alignment with other parts of my device which is ordinarily mounted directly thereabove for cutting and patching veneer sheets. vFor example the block 42 may be Vshifted longitudinally by backing off adjustment screw 43 while advancing a similar adjustment screw 44.

Fitted into an opening 46 within the base-block 42 is a ram or plunger member 46 that has a shank 41 extending downwardly therefrom into a chamber in the cylinder 48 which depends from the base member 62. shank 41 is shouldered at 50 and a coil spring 5i encircling the shank is seated between the iiange ring 62 in the upper portion of the chamber and the shoulder 50 below to constantly urge the member I26 downward. At its lower end the shank 41 is associated with the diaphragm 54 in the diaphragm chamber or housing 66 to which air or other fluid pressure means may be supplied and exhausted by means of the tube 66 and vent 66.

Above the base member 42 is a cutting die 60 which has an interior passage 62 that is normally aligned with the opening 46 on the base 42. The die 60 is so formed that it has acutting or shearing edge at its upper end as well as one on its lower end of the opening 62.

On the upper amr of the frame 20 is mounted a cylinder 64 having an upper flange 66 that rests upon a suitable support member 66 associated with the arm. vAn auxiliary cylinder 68 depends also from flange 66 and encloses in spaced relation the cylinder 64. Positioned therebetween is the clamping shoe 10 having a -foot 1| and an enlarged head 12 adapted to close the area between the cylindrical walls 64 and 68. An expansion coil spring 14 is positioned between a flange 66 on the cylindrical wall 66 and the under side of the head 12 of the clamp member 10 and constantly urges the member 10 upwardly.

Air supplied to the -chamber 16 through the conduit 16 will permit the downward extrusion of the clamping member 10 into a clamping position upon a sheet of veneer stock indicated by the numeral 26. g

Mounted for sliding movement in the inner face of the wall 84 is a `knife member 80 which will hereinafter be described as circular although it will be apparent that the shape of the knife may conform to the shape of any of the patch plugs that are suggested in the bracketed view of Figure 3. For example the circular plug 82 could be cut by the member 80, whereas a diamond-shaped plug 83, an oval plug 84, or a boat-shaped plug 86 would be cut by tools shaped for that purpose.

The knife member is engaged on the lower end of a tube 86 and is held in place by means of the nut 61. The upper end of the tube 66 is associated with the diaphragm 68 in the housing 60 to which air or other fluid under pressure may be supplied and from which it may be exhausted by means of the tubes 62 and 64.

A vertically movable shank 96 is slidably mounted in the nut member 81 and in an upper journal extension 91 of the tube 86. On its lower end the shank 96 has the pressure foot or shoe 96 that, in the case of the circular knife or cutter 80, is slightly smaller in diameter and adapted to be enclosed thereby on occasion.

On the upper end, shank 96 has the piston |00 mounted in the cylinder |02 to which air under pssure may be supplied through the conduit The piston |00 is normally urged upwardly as is also the shank 66 and the shoe 96 by means of a coil spring |06 positioned between the under side gf the piston and the bottom of the piston cham- For introducing a plug-blank 34 yto the under side of the die 60 or between member 42. and member 60 I employ the transversely slidable carrier bar ||0 which has an offset arm to which may be connected the rod l I2 of the piston ||3 within the chamber ||4. The piston ||3 may be moved either to the right or to the left, as seen in Figures 5 and 5A by air or other fluid under pressure supplied to the tubes ||6 and ||6.

A slot H8 in the carrier bar is provided and has suiiicient width to fit either side of the holddown member 42 and to slide on either side of that member while at the same time advancing one of the plug-blanks .34 in the opening ||6 in the arm into position for cutting. On its advanced or forward end the carrier or bar ||IJ carrying a clean-out bar r cross-head |20 which travels across the upper face of the member 42 and the member 46 and will wipe therefrom any debris from the veneer sheet cutting operation that may be deposited thereon. Spring |22 operates upwardly against the under side of the plug blank as it is being fed to the carrier bar to the cutting position and holdsit against dislodgement during that travel.

To assist in cleaning o'ut any debris that may remain in the carrier arm ||0 after a blank has been cut into the proper shape for a patch, I employ the upwardly urged spring leaf |22 that may best be seen in Figures 1 and 13 and which rides in the slot |8 and the opening H9 and will deflect downwardly any such debris therein.

' In the showings of the Figures 9 through 14,' are illustrated, the various elements of the invention and the steps of the method by which the invention is practiced.v In the Figure 9 I have shown fragments ofthe essential portions of the mechanism and this mechanism is shown in the at rest position. In this position the veneer sheet 28 is inserted between the member 60 and the clamping mechanism positioned thereabove so that the marred area 28a that is to be cut from the sheet 28 is within the effective cutting area 0f the knife 8U.

In Figure 10 the rst mechanical movement of the device is illustrated as having occurred. In

that case the sheet 28 is clamped on the die 60 by means of the clamp mechanism l0 which is extruded downwardly from its upwardly supported position on the spring 14, through the urgence of air which has been introduced into chamber I5 against the upper face of the member 16 through the tube 16. When airis supplied to the tube 16 the member 1U seats firmly so that its foot 1| sheet 28 and holds it tightly in place.

The next step in the method is illustrated in Figure 11 in which instance the knife 80 and the hold down member 98 have been forced downwardly under the urgence of 'air applied to the upper surface of the diaphragm 88 and also into the chamber |02 against the piston |00.

The thin knife edge of the member 86 shears out the marred portion 28a of the sheet 28 that is to be cut away and carries it downwardly. The debris is removed from within the knife by means of the foot 98 stripping it therefrom as the member 86 is withdrawn. This latter operation can be clearly seen in Figure 12 in which instance it will be noted that the clamp member 'l0 is still firmly holding the sheet 28 against the die 60. The debris or marred area' 28a that has been cut away is now lying on the upper surface of the upwardly movable ram member 46, from which it is to be removed by the operation of the laterally movable cross-head I on the carrier arm H0. Arm ||0 moves across the upper face of member 46, between members 42 and 6U, so that, as will be seen in Figure 13, the debris 28a is kicked out of the mechanism and falls in a suitable manner for disposal.

At the same time, through the movement of the carrier arm across the member 40, a patching blank 34 is carried into position onto the upper face of the member 42 under the hold-down shoe 98. When a patch 34 is properly positioned under the die 60 the upwardly moving plunger 46 rises under the urgence of air supplied to the underl side of the diaphragm 54 and the plug blank 34 that will expand when freed from the die is securely clamped between the ram and member 98 as it passes against the lower cutting edge of the die member 60 and through the opening or passage 62 therein. The cutting operation ,will

bend certain of the wood fibers along the cut edge block to grip the inner edges of the opening in the ,veneer sheet. The cut plug patch is held under presses against the upper face of the Vtioned operation may compression from top and bottom between the members 98v and the lower ram member 46 all of the time that it passes through the opening 62 in the cutting die 60. The plug and its bent bers along the edge are held against edgewise expan- -sion by the walls of the opening or passage 62 of the member 60 so that the patch plug has no opportunity to expand larger than its cut size. This compression is maintained all of the time until the plug shown in Figure 14 is brought into position in the member 28 whereupon the plug body and edge fibers are freev to expand in thc opening therein.

By means of suitable timing mechanism, these various-steps hereinabove described are carried on sequentially with split-second timing where necessary. The details of such control mechanism is not shown as many types would perform suitably such simple functions.

The moment that the plug is placed in the opening as shown in Figure 14, the shoe 98 rises and the ram 46 is forced downwardly by the action of the spring 5| or by means of air that may be supplied to the upper side of the diaphragm 54. The cutting and to the at rest patching mechanism returns position as shown in Figure 9.

position'of Figure 5A to that of Figure 5, and any debris 34a that may be on the upper face of the member 42 is withdrawn, to the left in the showing, and is stripped from the slotted carrier arm H6 bymeans of the tends into the slot I8. In Figure 1 this last menbe seen with the debris shown as falling out of the carrier arm and downwardly for disposal by gravity or otherwise.

` The upper and lower diaphragms 64 and 88, are ordinarily controlled by means of a supply of air or other fluid under pressure which passes through the valve mechanisms 55 and 69 respectively. These valve mechanisms may be of the solenoid operated type, arid an electrical ccntroller means (not shown in the drawings) will control the opening and closing of these valves, permitting the influx or exhaust of air to the diaphragms. In such cases where there is no direct supply of air furnished to the diaphragms to return them to the original or at rest position, this function is performed by the springs 5| and 8l. LAir may freely flow in or out through the members 58 and 94 so that exhaust may be provided to break the vacuum on retracting movement. The supply of air pressure to the chamber 92 to the Valve |03 is controlled by the electrically operated mechanism |03a indicated in Figure 1.

It will be noted that during practically all of the operations of my invention in cutting and patching a sheet of veneer that the holding or clamping mechanism is constantly maintaining the sheet against the die to hold'it in position during the punch cutting operation, as well as during the patching cycle.

The clamp means is so constructed that itA surrounds the punch and also the area to be punched- `cut and prevents breaking or cracking of the wood during the punching cycle. This is extremely 1mportant for, in fibrous wood as well as in brittle leaf spring |22 which eX- sheets, if the material being cut were not ilrmly held it would tend to splinter and to crack and to otherwise destroy itself when the knife is brought downwardly to perform its shearing function. It is to be noted that .the important operation of cutting lthe required area from a sheet of veneer stock is performed by a knife that moves and cooperates with a fixed die and that this cutting operation is not merely a punching or stamping operation but also a shearing operation. The former is impractical because of the large sheet being cut and because the material within the cutis usually weak and will not stand punching. The converse is true when the'plug patch blank is cut to form a patching plug for in that case the stock is suiliciently strongto be forced upwardly against a ilxed die due to the operation of the vertically rising plunger.

While I have shown as a preferred form of my invention, and piston mechanisms for the: actuation ofthe various mechanical elements of my device it is to be understood that these form no important part of my invention as the combination of elements forming the cutting mechanism is the heart and soul of the invention.

I claim:

l. In the patching of veneer sheets having a marred area, Athe method which comprises: clamping the veneer sheet so that the area surrounding the portion to be cut is rigidly held, punch cutting the marred area .from said sheet and disposing oi the debris removed thereby, sequentially clamping a punched blank and cutting it to the size and shape of the punch cut area. inserting said cut plug in said opening in the sheet without having unclamped the sheet the use or air-operated diaphragms d assavos ly clamped, sequentially clamping a plug blank and cutting it to the size and shape of the punch cut area. and inserting said cut plug in said opening in the sheet without having unclamped the sheet while simultaneously maintaining said plug compressed against buckling and edgewise expansion.

3. In the patching' of veneer sheets having a marred area,I the method which comprises: clamping said sheet so that the area surrounding the portion to be cut is rigidly held. punch cutting the marred area from said sheet and disposing of the debris removed thereby, sequentially clamping a plug blank and cutting it to the size and shape of the punch cut area so that the cut edge has bent fibers, and inserting said cut plug in said opening in the sheet without having unclamped the sheet while simultaneously malntaining said yplug compressed against buckling and edgewise expansion.

4. The method of inlaying sheet material,

which method comprises: punch cutting a sheet i to be inlaid while simultaneously and thereafter,

while simultaneously maintaining said plugV pressed against buckling and edgewise expansion, and finally unclamping said sheet.

2. In the patching of veneer sheets having a until the inlay operation is complete, maintaining the area surrounding the opening free fromv distortion; clamping an inlay blank on opposite faces and cutting an inlay to the size and shape of ther punch-cut opening; .simultaneous with the cutting, securing the inlay by restraining pressure exerted transversely of its axis while maintaining the clamping pressure on the opposite inlay faces; and inserting the inlay into the punch cut opening.

PER F. SKOOG. 

